Lincoln Electric IM663 RED-D-ARC D300K 3+3 - Manual (Page 14)

B-2 OPERATION B-2
WELDER OPERATION
Duty Cycle
The output rating of the D300K 3+3 is 250 amperes at
40 arc volts on a 60% duty cycle. Duty cycle is based
on a ten minute period; thus, the welder can be
loaded at rated output for six minutes out of every ten
minute period.
Control of Welding Current
DO NOT TURN THE “CURRENT RANGE SELEC-
TOR” WHILE WELDING because the current may
arc between the contacts and damage the switch.
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The “Current Range Selector” provides five overlap-
ping current ranges. The “Fine Current Adjustment”
adjusts the current from minimum to maximum within
each range. Open circuit voltage is also controlled by
the “Fine Current Adjustment” permitting control of the
arc characteristics.
A high open circuit voltage setting provides the soft
“buttering” arc with best resistance to pop-outs pre-
ferred for most welding. To get this characteristic, set
the “Current Range Selector” to the lowest setting that
still provides the current you need and set the “Fine
Current Adjustment” near maximum. For example: to
obtain 175 amps and a soft arc, set the “Current
ELECTRIC SHOCK can kill.
• Do not touch electrically live parts or
electrode with skin or wet clothing.
• Insulate yourself from work and ground.
FUMES & GASES can be dangerous.
• Keep your head out of the fumes.
• Use ventilation or exhaust to remove
fumes from breathing zone.
WELDING SPARKS can cause fire or
explosion.
• Keep flammable material away.
ARC RAYS can burn.
• Wear eye, ear, and body protection.
WARNING
CAUTION
D300K 3+3
BREAK-IN PERIOD
Lincoln Electric selects high quality, heavy-duty indus-
trial engines for the portable welding machines we
offer. While it is normal to see a small amount of
crankcase oil consumption during initial operation,
excessive oil use, wet stacking (oil or tar like sub-
stance at the exhaust port), or excessive smoke is not
normal.
Larger machines with a capacity of 350 amperes and
higher, which are operated at low or no-load condi-
tions for extended periods of time are especially sus-
ceptible to the conditions described above. To
accomplish successful engine break-in, most diesel-
powered equipment needs only to be run at a reason-
ably heavy load within the rating of the welder for
some period of time during the engineʼs early life.
However, if the welder is subjected to extensive light
loading, occasional moderate to heavy loading of the
engine may sometimes be necessary. Caution must
be observed in correctly loading a diesel/generator
unit.
1. Connect the welder output studs to a suitable
resistive load bank. Note that any attempt to short
the output studs by connecting the welding leads
together, direct shorting of the output studs, or con-
necting the output leads to a length of steel will
result in catastrophic damage to the generator and
voids the warranty.
2. Set the welder controls for an output current and
voltage within the welder rating and duty cycle.
Note that any attempt to exceed the welder rating
or duty cycle for any period of time will result in cat-
astrophic damage to the generator and voids the
warranty.
3. Periodically shut off the engine and check the
crankcase oil level.